PEOPLE who eat fish once a week are five times less likely to develop Alzheimer’s disease, says a new study.

Researchers found that grilled or baked fish is good for the brain and can lower the chances of developing mild cognitive impairment (MCI).

This condition is often seen as a pre- cursor to full-blown Alzheimer’s.

It has long been known that fish is beneficial for health. Studies have shown it can slash the chances of developing cancer, heart disease and a host of life-threatening illnesses.

It is thought beneficial fatty acids in the fish are key to helping lower the risk of dementia.

Now US scientists have found that eating fish regularly appears to boost the size and health of the brain’s neurons. This means fish eaters are up to five times less likely to develop Alzheimer’s as those who avoid it.

Researchers from the University of Pittsburgh, who will present their study at the annual meeting of the Radiological Society of North America today, say eating fish helps preserve the brain’s grey matter, stopping its cells from shrinking and dying off.

They studied 260 people with healthy brains, 160 of whom ate fish at least once a week.

MRI scans showed the fish eaters had less deterioration of brain cells in areas associated with Alzheimer’s, like the hippocampus, over 10 years.

The study also found that fish can help boost memory – which has led to it already being dubbed a “brain food”.